Throughout Olivia Thompson's 12-hour shift as a cardiac and Covid-19 nurse in Chandler, Arizona, she closely monitors the oxygen levels of several patients at a time and works with other medical specialists to heal them. For some, no amount of care Thompson gives prevents them from being transferred to the Intensive Care Unit. "There were times where I was dreading going to work because of the unknown," Thompson said. "Am I going to be a good nurse for my patients? Am I going to make a mistake?"